Fatty acid-acylated borates as gasoline and lube oil additives



United States Patent 3,151,077 FATTY AClD-ACYLATED BORATES AS GASOLINE AND LUBE OIL ADDITIVES Chien-wei Liao, Beachwood, Ohio, assignor to The Standard Oil Company, Cleveland, Ohio, a corporation of Ohio No Drawing. Filed Mar. 6, 1961, Ser. No. 93,248 3 Claims. (Cl. 252-49.6)

This invention relates to organic boron compounds which may find use as additives for liquid hydrocarbon stocks such as motor fuels, i.e., gasoline or jet fuel, fuel oils, and lubricating oils. More particularly, the invention relates to borated monoacylated trimethylol alkanes and to their use as motor fuel additives.

It is well known that during the operation of an initially clean internal combustion engine running on a hydrocarbon fuel, deposits gradually build up on the surfaces of the engines combustion chamber. The adverse effect of such deposits manifests itself in uncontrolled ignition and a general lack of smoothness in engine operation, caused principally by the deposits on the combustion chamber surfaces becoming heated to incandescence during engine operation, and igniting the fuel either before or after that portion of the cycle where normal spark plug discharge would cause ignition. This phenomenon is commonly referred to as surface ignition.

The deposit problem is aggravated by the presence in the fuel of a tetra-alkyl lead anti-knock compound, because the deposits are then no longer essentially carbonaceous, but contain appreciable quantities of lead and lead compounds in admixture with carbonaceous material. These mixed deposits are more tenacious and troublesome than a pure carbonaceous deposit, despite the fact that one or more organic halides may be present in fuel as lead scavenging agents.

It has been found that the incorporation of minor amounts of the organic boron compounds of this invention to motor fuels in some manner modifies the nature of the combustion chamber deposits formed, so as to decrease the incidence of surface ignition.

Deposits are also known to build up on the surfaces of carburetor internals, viz., carburetor walls, throttle valve, jets, and venturi. Such deposits are believed to accumulate from contaminants borne by the copious quantities of intake air an operating carburetor breathes. The situation is aggravated by prolonged engine operation in urban and industrial areas where the concentration of contaminants in the air is high. Since these deposits can result in rough idling and frequent stalling, their inhibition is distinctly advantageous. It has been found that the incorporation of minor amounts of the organic boron compounds of this invention in motor fuels is elfective in inhibiting the formation of carburetor deposits.

It is therefore an object of this invention to prepare novel organic boron motor fuel additives.

Another object is to provide a motor fuel containing an additive which successfully reduces the incidence of surface ignition in an internal combustion engine.

A further object is to provide a motor fuel containing an additive which is effective in inhibiting the buildup of carburetor deposits.

Other objects and advantages will become apparent from the following detailed description of the invention.

3,151,011. Patented Sept. 29, 1964 The boron compounds suitable for use according to this invention have the following general formula:

where R is an alkyl group having from 1 to 6 carbon atoms; R and R" are selected from the group consisting of a hydrogen atom and an alkyl radical having from 1 to Scarbon atoms; and R and R" may be the same or different in the compound; R' is selected from the group consisting of alkyl and alkenyl radicals having from 7 to 20 carbon atoms, and naphthenyl radicals having from 10 to 20 carbon atoms; and X is selected from the group consisting of hydrogen and I one R o \I CHO Rl/I theoretical.

' or a lubricating oil) to which the boron compound is to be added. It the solvent does not form an azeotrope with water, enough of an azeotropic forming agent is included to remove the water azeotropically.

EXAMPLE I Borated, Oleated Trimethylol Propane (l) 201 grams of trimethylol propane and 423 grams of oleic acid (a 1:1 molar ratio) were mixed together in 300 ml. of xylenes. The mixture was heated with stirring at reflux until 27 ml. of water (the theoretical amount to form the mono-acylated intermediate) were removed by azeotropic distillation.

(2) 478 grams of the mono-acylated intermediate and 74.3 grams of boric acid (a 1:1 molar ratio) were mixed together in 240 ml. of xylenes. The mixture was heated with stirring at reflux until 54 ml. of water (the theoretical amount to form the borate anhydride) were removed by azeotropic distillation. Boron analysis of the resulting product showed 2.54% B, compared with 2.60% B EXAMPLE II Borated, Nonanoated, T rimerhylol Propane (1) 13.4 grams of trimethylol propane and 15.9 grams of nonanoic acid (a 1:1 molar ratio) were mixed together in500 ml. of xylenes. The mixture was heated with stirring at reflux until 1.8 ml, of water (the theoretical amount to form the mono-acylated intermediate) were removed by azeotropic distillation.

(2) 27.5 grams of the mono-acylated intermediate and 6.2 grams of boric acid (a 1:1 molar ratio) were. mixed together in 500 ml. of xylenes. The mixture was heated with stirring at reflux until 4.5 ml. of water (the theoretical amount to form the borate anhydride) were removed by azeotropic distillation.

Boron analysis of the resulting product showed 3.7% B, identical to theoretical.

EXAMPLE III Borated, Laurolated T rimethylol Ethane (1) 12.2 grams of trimethylol ethane and 200 grams of lauric acid (a 1:1 molar ratio) were mixed together in 200 ml. of xylenes. The mixture was heated with stirring at reflux until 18 ml. of water (the theoretical amount to form the mono-acylated intermediate) were removed by azeotropic distillation.

(2) 152 grams of the mono-acylated intermediate and 31 grams of boric acid (a 1:! molar ratio) were mixed together in ml. of xylenes. The mixture was heated with stirring at reflux until 22.5 ml. of water (the theoretical amount to form the borate anhydride) were removed by azeotropic distillation. Boron analysis of the resulting product showed 3.03% B, compared with 2.81% B theoretical.

EXAMPLE IV Boraled, Nonanoaled Trimethylol Ethane stirring at reflux until 18 ml. of water (the theoretical amount to form the 'mono-acylated intermediate) were removed by azeotropic distillation.

(2) 197 grams of the mono-acylated intermediate and 46.3 grams of boric acid (a 1:1 molar ratio) were mixed together in 187.5 ml. of xylenes. The mixture was heated with stirring at reflux until 33.7 ml. of water (the theoretical amount to form the borate anhydride) was removed by azeotropic distillation.

It will be understood that mixtures of fatty acids may also be used in the above preparation. Commercially available mixtures include those derived from tallow and naturally occurring oils, such as cottonseed oil, soybean oil, coconut oil, tall oil, and the like.

Since pure naphthenic acids are not readily available,

a mixture of naphthenic acids was used in the following preparation. The mixture used was Eastmans yellow label (practical grade). naphthenic acids having a boiling point range of 160498 C./6 mm, and an average molecular weight of 230.-

(l) '134 grams of trimethylol propane and 230 grams of naphthenic acids (an approximated 1:1 molar ratio based on the average molecular weight of the naphthenic acids) were mixed together in 300 ml. of xylenes. 'The mixture was heated with stirring at reflux until 17.8 ml. of water was removed by azeotropic distillation (18 ml. of water is the theoretical amount to form the monoacylated intermediate).

(2) The resulting monoacylated intermediate in xylenes was mixed with 61.8 grams of boric acid (an approximated 1:1 molar ratio). The mixture was heated with stirring at reflux until 44 ml. of water (theoretical 45 ml.) was removed by azeotropic distillation, to form the borate anhydride.

The reaction can similarly be carried out with u,adimethyl trimethylol propane, a,a'-biS isopropyl trimethylol hexane, a,a-diethyl trimethylol pentane, a,ii'-dibl.1tyl trimethylol heptane, vt-ethyl, oU-isopropyl trimethylol ethane, and the like.

Gasoline base stocks to which the organic boron compounds of this invention can be added are any of those conventionally used in preparing a motor gasoline for a spark-ignited internal combustion engine; such as catalytic distillate, motor polymer, alkylate, catalytic reformate, isomerate, naphthas, etc. erably contain a tetra-alkyl lead compound as an antiknock agent, and a scavenging agent. The amount of the anti-knock agent will be usually at a level of approximately 3 ml./gal., but may range from mL/gal. up to 6 ml./ gal. The base gasoline may also include other common additives such as anti-oxidants, stabilizers, solvent oils, dyes, and the like.

The amount of organic boron compound to be added to gasoline to accomplish the purposes of this invention may vary, and is conveniently express in terms of percent by weight of boron. Excellent results have been obtained where the amount of compound is within the range of .0005% to .008% boron by weight. Usually amounts The gasoline will pre'fgreater than .l% boron by weight cannot be economically justified. The compounds may be added directly to the gasoline, or as previously noted, they may be added in the form of a liquid concentrate in the solvent used in their preparation, provided said solvent is compatible with the gasoline.

SURFACE IGNITION TEST (A) Procedure.-An ASTM-CFR single-cylinder engine having a compression ratio adjusted at 12:1 was employed. Preparatory to each test cycle, the engine was run open throttle at 900 r.p.m. for thirty minutes to stabilize the engine operation on the test fuel. After thirty minutes, with the engine continuing to operate at open throttle, the total surface ignition count was observed electronically and recorded over a threehour period. All experimental conditions were the same for each test cycle except for the fuel additive.

The base fuel employed throughout this test had the following composition and specifications:

(B) Test results.The surface ignition counts of the modified fuels are expressed as percentages of the surface ignition counts of the base fuel. The concentration of additive is expressed as wt. percent B i.e., that amount of additive which will supply the fuel with the stated weight percent of boron.

TABLE I SI rating of Fuel Fuel Wt.

Percent 13 Total SI Audible SI Base none 100 100 Baso-l-BLTE 1 0.002 56 56 1 Borated, laurated trirnethylol ethane.

It can readily be seen that a base fuel modified with an organic boron compound of this invention significantly reduced both total and audible surface ignition counts.

CARBURETOR CLEANLINESS. TEST (A) Procedure.In this test, a contamination system was developed to simulate the conditions which contribute to carburetor deposits in the urban operation of motor vehicles. The system comprises the operation of a slave engine and a test engine. The exhaust gases from one bank of slave engine cylinders (four) are metered to the crankcase of the test engine at a rate of 1.5 cubic feet per minute. All gases from the crankcase of the test engine are passed to the air intake of the carburetor of the test engine including, therefore, the exhaust gases from the slave engine and the blowby fumes of the test engine. The 1.5 cubic feet per minute rate of exhaust gases from the slave engine under these conditions constitutes approximately 8% of the total air intake of the test engine at idle manifold vacuum and speed. The

specifications and operating conditions for the two engines include the following:

Each test cycle was two hours in duration and included four acceleration periods conducted at half-hour intervals on the unloaded test engine. The first acceleration period occurred thirty minutes after the test cycle commenced. During each acceleration period the throttle was moved quickly to a wide open position and then quickly closed again to an idle position five separate times, to permit recurrent surges of gasoline to come into contact with carburetor parts. The test engine carburetor at the start of each test cycle was in spotless condition. All experimental conditions were the same for each test cycle except for the fuel additive.

The base fuel employed throughout this test was composed of 75% catalytic distillate and 25% straight run naphtha.

(B) Test results.At the end of each test cycle the test engine carburetor was removed, disassembled and inspected. The rating assigned was based on a standardized scale ranging from 10 to 0, wherein 10 would be a rating for a perfectly clean carburetor throttle plate and barrel, and 0 would be a rating for a carburetor throttle plate and barrel loaded with deposits. The numerical rating of the base fuel was 5. The deposits and discoloration produced by base fuel modified with the addtives of this invention were then rated in terms of units of improvement over the base fuel rating. The concentration of additive is expressed as wt. percent B i.e., that amount of additive which will supply the fuel with the stated weight percent of boron.

TABLE II Rating Im- Fuei Wt. percent provement B over Base (Base =5) None 0. 001 +1. 5 0. 002 +2. 3 0. 001 +0. 7 0. 002 +2. 0

1 Borated, oieated, trimethylol propane. 1 Borated, nonanoated, trimethylol propane.

It can be seen from Table II that as low a concentration as 0.001% boron produces a sigificant improvement, while at 0.002% boron, the improvement is substantial.

It is to be understood that various modifications of the present invention will occur to those skilled in the art upon reading the foregoing disclosure. It is intended that all such modifications be covered which reasonably fall within the scope of the appended claims.

I claim:

1. A gasoline containing a compound having the formula I RI! where R is an alkyl group having from 1 to 6 carbon where R, R, R" and R' are defined the same as above, said compound being present in an amount equivalent to at least 0.001 wt. percent boron based on the Weight of gasoline.

2. The gasoline of claim 1 which additionally contains a tetra-alkyl lead anti-knock compound at a concentration within the range of 0.5 to 6 ml./ gal. of gasoline.

3. A liquid hydrocarbon material selected from the group consisting of fuels and lubricating oils containing a compound having the formula where R is an alkyl goup having from 1 to 6 carbon atoms; R and R are selected from the group consisting of a hydrogen atom and an alkyl radical havingfrom 1 to 3 carbon atoms; R is selected from the group consisting of alkyl and alkenyl radicals having from 7 to 20 carbon atoms and naphthenyl radicals having from 10 to 20 carbon atoms; and X is selected from the group consisting of hydrogen and where R, R, R and R' are defined the same as above, said compound being present in an amount equivalent to at least .001 wt. percent boron, based on the weight (if stock.

References Cited in the file of this patent UNITED STATES PATENTS 2,805,135 Bell et al Sept. 3, 1957 2,847,444 Gardner Aug. 12, 1958 2,894,020 McManimie July 7, 1959 2,948,598

Brehm Aug. 9, 1960 

3. A LIQUID HYDROCARBON MATERIAL SELECTED FROM THE GROUP CONSISTING OF FUELS AND LUBRICATING OILS CONTAINING A COMPOUND HAVING THE FORMULA 